NBC NATIONAL NEWS — Despite users threatening to leave Instagram after the image-sharing service proposed changes to its terms of service, it appears overall user numbers haven't suffered much. In fact, that number may be growing ... slowly.

Instagram recently revealed that it currently has 90 million monthly active users. Co-founder Kevin Systrom explained to AllThingsD's Mike Isaac that overall monthly active user numbers are up ten percent, from December to January. We're taking Systrom's word on this, because this is actually the first time Instagram has released data in terms of monthly active users. (Though it did previously reveal when it hit 100 million users.)

Now, what about the scattered reports of Instagram's doom and a user exodus? Isaac explains that those may have been due to daily active user statistics provided by third-party analytics tools. Daily active user numbers are bound to see significantly more fluctuations than the monthly counts.

If you're looking to put Instagram's numbers into perspective, consider that Facebook — which owns the image sharing service — announced that it has over one billion monhtly active users back in October 2012. Google+, in early December 2012, had 135 million.